1. Field of the Invention
The present invention relates to a method for detoxifying toxins or contaminants, particularly ammonia, chloramine and/or chlorine, from aquatic environments. In addition, the present invention is directed to a method for preparing a contaminant-detoxifying composition and the composition produced thereby.
2. Description of the Prior Art
Aquatic systems which support aquatic life generally comprise two types: the closed aquatic system and the open aquatic system. Further, aquatic systems can be divided into the naturally occurring aquatic systems and the artificial or man-made aquatic systems. Thus, naturally occurring closed aquatic systems include ponds and lakes, wherein a relatively fixed amount of water is present. Artificial closed systems include aquariums, such as household aquariums, man-made fish ponds for various uses, such as aquaculture, and other holding tanks used for storing, breeding and transporting fish and other aquatic life. Naturally occurring open systems include streams, while artificial open systems include flow-through systems, such as raceways used to raise trout. In such open systems, fresh (i.e., clean) water is continuously fed to the fish holding structure while a like quantity of water is continuously removed from the structure.
It is known in the biological arts that urea is excreted by animals as a result of normal animal metabolism and is rapidly converted into ammonia by biological action, primarily bacterial action. In aquatic systems, fish and other aquatic animal life excrete urea directly into the water, which is also rapidly converted into ammonia. Ammonia is also present in aquatic systems as a result of the decay of plant life, animal waste and uneaten food. If allowed to build up in an aquatic system, ammonia reaches toxic levels, causing sickness and death of aquatic life. Ammonia and other toxin buildup is not a particular problem in open aquatic systems, where fresh (i.e., clean) water continuously flushes away such toxins. However, such open systems are costly and inefficient for aquaculture purposes, which is generally the breeding, raising, storing and transporting of fish and other aquatic life for food and other purposes. Naturally occurring and closed systems, on the other hand, have traditionally proven difficult to maintain due, in part, to ammonia buildup.
In addition, especially in smaller, man-made closed systems, such as aquariums for home use, water for such use is often derived from municipal or public utility sources, where the water has been chlorinated to disinfect and sanitize the water. Thus, an additional problem confronting the closed aquatic system user is the presence of chlorine. Moreover, chloramines may be present for the same reasons as chlorine and, further, as a result of the chemical reaction of chlorine with ammonia.
Ammonia, chlorine and chloramines are contaminants deadly to fish and other aquatic life, such as aquatic plants and marine algae, snails and other aquatic invertebrates. For this reason, it is desired to remove, neutralize or otherwise detoxify these contaminants to leave an aquatic system safe and non-toxic to aquatic life.
As used herein with respect to the present invention, "detoxify" means to reduce the toxicity of ammonia, chlorine or chloramines to a level at which plant and animal aquatic life are not killed or otherwise irreversibly harmed or irreversibly stressed, regardless of the chemical, biological or biochemical mechanism causing such results.
Conventional methods for removing ammonia in water include the use of zeolite in the form of loose chips, granules or powder through which the water must be passed. Conventional methods for detoxifying chlorine and chloramines in water include passing the water through activated carbon in the form of loose chips, granules or powder. Such methods, however, are generally inconvenient and inefficient because the zeolite or activated carbon chips, granules or powders are messy to handle and must be added to a filter container. Moreover, the amount of zeolite or activated carbon necessary to efficiently detoxify a given quantity of ammonia or chlorine from an aquatic system is difficult to measure.
Chlorine and chloramines have also been neutralized in aquatic systems by chemical means, such as by adding sodium thiosulfate, sodium bisulfite, sodium hyposulfite or sodium metabisulfite.
U.S. Pat. No. 4,666,610 discloses a method for the removal or neutralization of chloramines, chlorine and ammonia from aquatic systems by adding an alkali metal formaldehydebisulfite to the aquatic system. However, the method disclosed by this patent appears to merely neutralize the chloramines, chlorine and ammonia for a short time after the neutralizing compound is added. Tests have indicated that the compound disclosed by this prior patent is stable for only a few days, after which the ammonia appears to be released back into the system. In addition, the compound is acidic, which can lower the pH of the aquatic system and increases the risk of pH shock to any fish present. Moreover, the alkali metal formaldehydebisulfite is toxic to saltwater invertebrates, such as corals, and appears to be generally incompatible with commonly used aquatic disease remedies, such as malachite green, methylene blue and acriflavine.
In view of the deficiencies and inefficiencies of the prior art, it would be desirable to have a method for detoxifying ammonia in aquatic systems that is safe, non-toxic, easy to use and is capable of keeping the aquatic system substantially ammonia free for an extended period of time. Further, it would be desirable to have a method for detoxifying chlorine and chloramines in addition to ammonia that is safe, easy to use and non-toxic to aquatic life.